Steel sheet for hot press-forming (as amended)
a technology of steel sheets and hot pressforming, which is applied in the direction of heat treatment apparatus, manufacturing tools, transportation and packaging, etc., can solve the problems of deteriorating productivity, liquid-metal brittle fracture, and brittle fracture of metal, and achieve excellent liquid-metal brittle resistance, short transfer time, and improved productivity
Active Publication Date: 2016-05-26
JFE STEEL CORP
View PDF2 Cites 1 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
The present invention provides a steel sheet for hot press-forming with excellent resistance to liquid-metal brittle fracture even under fast production conditions. This steel sheet can be used to manufacture hot press-formed parts suitable for automotive underbody and body structural parts that have high liquid-metal brittle resistance. This improves productivity and efficiency of the manufacturing process.
Problems solved by technology
This can cause liquid-metal brittle fracture during hot press-forming, in which zinc in the coating layer enters the steel sheet and causes cracks.
However, when the steel sheet for hot press-forming described in Patent Literature 3 is subjected to hot press-forming after a short transfer time, liquid-metal brittle fracture can be caused.
This deteriorates productivity.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
example 1
[0043]A cold-rolled steel sheet having a thickness of 1.6 mm was used as a base steel sheet. The cold-rolled steel sheet had a composition consisting of C: 0.23%, Si: 0.25%, Mn: 1.2%, P: 0.01%, S: 0.01%, Al: 0.03%, N: 0.005%, Cr: 0.2%, Ti: 0.02%, B: 0.0022%, Sb: 0.008% on a mass percent basis, and the remainder being Fe and incidental impurities, and had an Ac3 transformation point of 820° C. The first coating layer and the second coating layer were formed in this order on both sides of the cold-rolled steel sheet by electroplating. Thus, steel sheets Nos. 1 to 16 were manufactured.
[0044]The first coating layer was formed in a plating bath containing 240 g / L nickel sulfate hexahydrate and 30 g / L boric acid at a pH of 3.6, at a bath temperature of 50° C., and at a current density of 5 A / dm2. The coating weight of coating layer was adjusted by changing the energization time. For the steel sheets Nos. 2 and 11, the Ni content was adjusted by the addition of zinc sulfate heptahydrate. T...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
| Property | Measurement | Unit |
|---|---|---|
| Percent by mass | aaaaa | aaaaa |
| Fraction | aaaaa | aaaaa |
| Fraction | aaaaa | aaaaa |
Login to View More
Abstract
A steel sheet for hot press-forming having a first coating layer on a surface of the steel sheet, containing 60% or more by mass Ni and a remainder composed of Zn and incidental impurities, a coating mass thereof being more than 5 g / m2 and 50 g / m2 or less per side, and a second coating layer on the first coating layer, containing 10% to 25% by mass Ni and a remainder composed of Zn and incidental impurities, a coating mass thereof being 10 to 90 g / m2 per side.
Description
CROSS REFERENCE TO RELATED APPLICATIONS[0001]This is the U.S. National Phase application of PCT / JP2014 / 002505, filed May 13, 2014, which claims priority to Japanese Patent Application No. 2013-132248, filed Jun. 25, 2013, the disclosures of these applications being incorporated herein by reference in their entireties for all purposes.TECHNICAL FIELD OF THE INVENTION[0002]The present invention relates to a steel sheet for hot press-forming that is suitable to produce automotive underbody parts and automotive body structural parts by hot press-forming.BACKGROUND OF THE INVENTION[0003]Most of the automotive underbody parts and the automotive body structural parts are manufactured by press-forming steel sheets having a predetermined strength at a room temperature. In recent years, from the perspective of global environmental conservation, there has been a strong demand for weight reduction of automotive bodies, and efforts have been made to reinforce steel sheets and thereby decrease th...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): B32B15/01C22C18/00C22C38/60C22C38/00C22C38/28C22C38/06C22C38/04C22C38/02C22C19/03C22C38/32
CPCB32B15/015C22C19/03C22C18/00C22C38/60C22C38/32C22C38/001C22C38/06C22C38/04C22C38/02C22C38/002C22C38/28C21D1/00C21D7/13C21D1/673C25D5/14C25D3/12C25D3/56C25D3/565C25D5/50C25D7/0614Y10T428/12799Y10T428/12944Y10T428/12937C25D5/617C25D5/60
Inventor NAKAJIMA, SEIJIMORIMOTO, MINAKOANDO, SATORU
Owner JFE STEEL CORP